Joint for connecting a longitudinal side to an upper side of components and flexible strip for use in such a joint

ABSTRACT

A joint arrangement connects a longitudinal edge of a first component with an upper surface of a second component. At least two cooperating bands are secured with their first ends respectively on opposite sides of the first component, and are secured with their second ends respectively on clamping elements arranged on the second component, so that the bands intersect the major center plane of the first component in the joint area between the components. A pressure element is positioned on at least one clamping element for supporting the first component, and the bands extend laterally next to the pressure element and crosswise relative to one another.

FIELD OF THE INVENTION

The invention relates to a joint for a component-arrangement, in which alongitudinal side of a first component faces toward an upper surface ofa second component, as well as a flexible band for use for such a joint.

For improving the aerodynamic characteristics of wings, concepts for awing with a variable profile that is adjustable via control mechanismsare known from the general state of the art. These concepts, however,use relatively many movable parts and joints, which mean a high effortand expense with respect to their fabrication and assembly.

For example, the U.S. Pat. No. 4,349,169 discloses a lifting wing with aprofile that is variable by means of an actuator drive. Drive rods ofthe actuator drive are connected by means of joints with the structureof the lifting wing, whereby the axial direction of the joints extendsin the span direction. Thereby, a profile variation is indeed possible,if plural actuator drives with corresponding operating rods are arrangedone behind another as seen in the span direction. The profile shapevariation disclosed therein, however, is achieved over the entire spandirection in this arrangement.

Furthermore, from the EP 860 355, there is disclosed an aerodynamiccomponent with variable camber, which is formed of articulatelysupported ribs with an outer belt and several stiffening struts thathave a constant length and that engage on this outer belt. For deformingthe component, the stiffening struts are operated by actuators in such amanner so that the stiffening struts move in the rib longitudinaldirection or flow direction.

From the DE 28 07 648 C2, a foldable wall is known, with wall partsconnected with one another through a fabric joint. The fabric joint is aband that is provided with a rim or edge rib on its longitudinal edges.The edge rib is held in a groove extending longitudinally along the sideface of the wall part with a corresponding recess that is wider relativeto the groove.

SUMMARY OF THE INVENTION

The object of the invention is to provide a joint that is simplyconstructed and simply installable, and represents an alternative to thepresently utilized joints.

This object is achieved with the characterizing features of theindependent patent claims. Further embodiments are set forth in thedependent claims.

According to the invention there is provided a joint for the connectionof a longitudinal side of a first component with an upper surface of asecond component with at least two cooperating bands, which are securedwith their first ends E1 respectively on different sides lying oppositeone another of the first component, and which are secured with theirsecond ends E2 on respectively one clamping element arranged on thesecond component in such a manner, so that these intersect thelongitudinal center axis of the first component in opposite directionsin the area between the components, with a pressure element forsupporting the first component positioned on at least one clampingelement, whereby the bands extend laterally next to the pressure elementand crosswise or transversely relative to one another as seen in theaxial direction. The bands can be formed of at least two plies of afiber-reinforced composite material or a different synthetic plastic ora textile material. The bands can extend in their longitudinal directionat an angle β relative to the axial direction of the structure-joint,whereby the angle β amounts to not equal to 90 degrees for taking up theshear forces to be transmitted through the joint. The bands can besecured between a clamping element and the second component.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, the invention is described in connection with theaccompanying figures. It is shown by:

FIG. 1 a schematic perspective illustration of an embodiment of theinventive joint, in which the kinetics and kinematics are entered in anarrow representation;

FIG. 2 the embodiment of the joint according to the FIG. 1 in section,with an arrow representation of the kinetics and kinematics;

FIG. 3 a further embodiment as a variant A of the inventive joint;

FIG. 4 a further embodiment as a variant B of the inventive joint;

FIG. 5 a further embodiment as a variant C of the inventive joint;

FIG. 6 a a schematic illustration of the shear force course or path inthe use of a flexible band for a joint, which, according to theinvention, is not fixed, but rather formed as a woven web, for example;

FIG. 6 b a schematic illustration of the shear force course or path inthe use of a flexible band for a joint, which is fixed in a matrix, thusfor example in a resin layer.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE INVENTION

Flexible joint-bands or bands or flexible straps or belt elements thatare constructed of at least two layers or plies of a material, wherebythe layers or plies are not fixed with one another in the free jointarea FG, are used for the inventive joints for the jointed orarticulated connection of two components that are movable relative toone another. In the following, that area or region that lies between thecomponents that are connected with one another, is understood as thefree joint region or area FG. The free joint area FG is also that areaof the bands, at which the bands of the joint do not lie in contact onthe components in each of the prescribed positions thereof. In contrast,each flexible band provided according to the invention comprises a fixedarea or region B, at which the band is secured to the respectivecomponent or is fixedly connected therewith. Areas or regions can alsobe included on these bands, which indeed lie in contact on the componentor the components, but which are not fixed or secured thereto.

The inventive joint is a structure-joint, because it can be formed, inits sub-parts, of materials that comprise similar characteristics as thecomponents that are connected with this, so that the behavior of thejoint corresponds to the behavior of the components even under theinfluence of forces or under tensions or stresses.

A fiber-reinforced composite (FRC) material or a different syntheticplastic or a textile material or woven web is especially provided as thematerial for the bands used according to the invention. The providedbands are formed of at least two plies of the above referenced material.The plies are not fixed to one another in the area FG, thus in theregion between the components T3, T4 that are to be connected with thejoint, in order to keep the shear forces FS of the arising shear forcepath or course V-FS as small as possible (FIG. 6 a). Otherwise, adisadvantageous course or path of shear forces FS would arise (FIG. 6b).

In the FIGS. 1 to 5 there is an inventive structure-joint or aninventive structure-joint arrangement for the connection of at least twocomponents T3 and T4, which are shown in a neutral position. In thisposition, the components form a T-arrangement. Fundamentally, thecomponents can form an angled arrangement in their neutral position. Thejoint connection shown in the FIGS. 1 to 5 serves for the connection ofa longitudinal side of a first component T4 with an upper surface of asecond component T3. The joint arrangement further includes at least onepressure element arranged between the longitudinal side and the uppersurface for forming a free joint area FG, and two flexible bandscooperating therewith.

According to the invention, there is provided a joint connection for theconnection of a longitudinal side of a first component T4 with an uppersurface of a second component T3 with at least two cooperating bands,which are secured with their first ends E1 respectively on differentsides lying opposite one another of the first component T4, and whichare secured with their second ends E2 on respectively one clampingelement arranged on the second component T3 in such a manner, so thatthe paths thereof in relation to a longitudinal center axis A of thefirst component T4 extend opposite one another or these intersect thelongitudinal center axis A of the first component in opposite directionsin the area between the components, with a pressure element positionedon at least one clamping element for supporting the first component T4,whereby the bands extend crosswise or transversely relative to oneanother as seen in the axial direction R1 and laterally next to thepressure element. Especially, the components, in interaction with the atleast one pressure element, form, laterally adjacent thereto, a freejoint area FG or two free joint areas, in which the bands respectivelyextend from one to the other component. Thereby, the bands can bearranged on one side of the pressure element or respectively one on bothsides thereof. Preferably, two pressure elements are provided, in orderto achieve a stable support of the pertinent component T4.

The bands can extend in their longitudinal direction at an angle βrelative to the axial direction R1 of the structure-joint, whereby theangle β can especially amount to not equal to 90 degrees for taking upshear forces to be transmitted through the joint.

The joint or joint arrangement 40 shown in FIG. 1 as a schematicprinciple illustration, comprises two arrangements with respectively twoflexible bands 41 a, 41 b or respectively 42 a, 42 b as well as a totalof three pressure elements 15, whereby one pressure element is locatedbetween the two arrangements of bands and respectively one pressureelement is located laterally next to the two arrangements of bands. Twoclamping elements 45, 46 in the form of clamping plates are arranged onthe component T3, whereby one clamping element 45 or 46 is positioned oneach side of the component T4.

The extension or path of the bands is as follows in the illustratedexample embodiment: Each flexible band 41 a, 41 b or 42 a, 42 b extendsfrom a first side of the component T4—for example the side 47—into thearea between the component T3 and the clamping element that lies next tothe component T4, and particularly on the side lying opposite to thefirst side of the component T4—thus in the example next to the side 48.From there, the flexible band extends around along the side of theclamping element 45 facing away from the component T4, onto the freeside of the clamping element facing away from the component T3, wherethe band is preferably secured. To each flexible band, at least onefurther flexible band is arranged, which is laid from the component T4around the clamping element opposite the described path. The kinematicsin this arrangement dependent on the angles α and β are illustrated inFIGS. 1 and 2. The angle α is the angle spanned by each respective oneof the bands 41 a, 41 b in the free joint area FG in relation to theupper surface of the component T3.

Particularly, the abovementioned relationships are given by

-   -   p=t*sinβ    -   S=Σt*cosβ    -   F=Σt*sinα*sinβ        wherein    -   p=pressure effective on the pressure elements    -   t=tension effective in the bands    -   S=external shear forces in axial direction R1    -   F=external tension forces in thickness direction R3    -   β=angle of bands relative to axial direction R1    -   α=angle of bands through free joint area relative to transverse        direction R2

Various different alternatives for the course or path of the bands andthe positions of the clamping elements relative to the component T4 areillustrated in the FIGS. 3 to 5, whereby respectively only two bands areshown. Fundamentally, two or more than two bands can be used for theinventive joint. The description of the path thereof is describedessentially in connection with one of the two illustrated bands. Thecourse or path of the at least one further band results correspondingly,in order to achieve a force flux opposite one another arising in thebands—as it is shown in the FIG. 2.

The respectively illustrated component T4 is oriented in its neutralposition with its crosswise or transverse planar direction R3 angularlyon the upper surface of the component T3. In FIGS. 3 to 5, as anexample, an angle of 90 degrees is illustrated for this neutralposition. Thereby, a first band 51 a is guided around a first clampingelement 52 a and a second band 51 b is guided around a second clampingelement 52 b as seen from the component T4, whereby the bands lie onebehind another as seen in the axial direction R1 of the joint or in thecorresponding longitudinal direction of the components in the free jointarea FG, and the bands' longitudinal directions run crossed-over oneanother. According to the invention, at least two cooperating bands areused, which are secured with their first ends E1 respectively ondifferent sides lying opposite one another of the first component T4,and which are respectively secured on a clamping element arranged on asecond component T3, whereby the positions of the clamping elementsallow a securing of the bands on sides that are opposite one another inrelation to a center axis A of the first component T4. Thus, accordingto the invention, the paths of at least two bands are opposite oneanother in relation to a longitudinal center axis of the first componentT4.

The clamping elements, together with the bands, are preferably securedby means of connection elements on the component T3. A pressure element15 is arranged in such a manner on one clamping element or on bothclamping elements (FIG. 5) so that the component T4 is supported in itsprovided joint positions on a corresponding bearing support surface 15 aof the pressure element 15. For that purpose, one or both clampingelements can respectively comprise a tongue Z or a contact area AB forreceiving a pressure element 15. A contact area AB can be arranged on atongue Z. The tongue Z of a clamping element protrudes into the areabetween the second component T3 and the side surface of the firstcomponent T4 facing toward this component T3. The tongues, lying onebehind another in the axial direction R2, of clamping elementssuccessively following one another in this direction, overlap oneanother. Since the bands contact or lie on these facing surfaces of thetongues Z, the bands are guided in such a manner, so that bands lyingrespectively next to one another as seen in the axial direction R1 crossone another in the free joint area FG (see FIGS. 3 to 5).

The two flexible bands 51 a, 51 b secured on the component T4 are usedin the embodiment according to the FIG. 3. Both clamping elementsprotrude with their cross-sections so far into the extension of thecomponent T4 in its crosswise or transverse planar direction R3, so thatthe bands beginning from the component T4 extend transversely relativeto one another and positioned next to one another in the free joint areaFG. A fictitious intersection point P of the bands arises as seen in thelongitudinal direction of the components T3, T4. This point P is theturning or pivot point of the joint.

The respective band, beginning from the component T4, after extendingthrough the free joint area FG, can be guided between the component T3and either the first clamping element 52 a or the second clampingelement 52 b, respectively, in order to then be secured on the freeupper surface of the pertinent clamping element 52 a or 52 brespectively. Beginning from one side of the component T4, each bandruns or extends through the free joint area FG up to the component T3,and crosses the longitudinal center axis A of the component T4 whileextending through the free joint area FG. From there, the band extendsaround the cross-section of one clamping element, and in fact at firstthrough between the two clamping elements, and then at least partiallyinto the area between one of the clamping elements and the component T3,and preferably around the free outer side of the same clamping elementup to a prescribed portion of the free outer side of the same clampingelement.

Each band is guided through an area that is kept free or clear of thetwo clamping elements to form a passage D. The position of thiskept-free or clear area is positioned either in the area of thecross-section of the extension of the component T4 in the directiontoward the component T3 (FIG. 5) or laterally next to this area (FIGS. 3and 4). This area D is, however, positioned in such a manner so that thepertinent band can be guided from one side of the component T4 to theother side thereof over the center axis A of the component T4 on thepivot point P in the free joint area FG. From there, either this bandextends in the direction in which it crosses the center axis A, to aclamping element (FIGS. 2, 4 and 5), where it is secured between thisclamping element and the component T3, or alternatively the band issecured between a clamping element and the component T3, on the sameside in relation to the center axis A on which it is secured on thecomponent T4 (FIG. 3).

The securing of the pertinent band on its first end E1 on the componentT4 is carried out in various different ways according to the state ofthe art. The band can be adhesively bonded or secured by means ofconnection elements on the component T4.

The fixing or securing of the bands on the component T3 can be achievedaccording to the state of the art, thus for example through adhesivebonding, through securing elements, or through a melting fusion of thematerials of the respective band with the respective component.

Preferably, the securing of the bands on their second end E2 on therespective clamping element is achieved by means of connection elements.In the FIGS. 3 to 5 it is shown on a first clamping element by means ofat least one connection element 54 a, that extends perpendicularly tothe component T3 and to the first clamping element 52 a, or 62 a or 72a, and that extends through the component T3, through the first clampingelement 52 a or 62 a or 72 a and the section of the band positionedtherebetween. Preferably, the pertinent band is guided around the rim oredge side 56 a of the clamping element 52 a or 62 a or 72 a facing awayfrom the component T4 onto outer side 57 a lying opposite to thecomponent T3. The first connection element 54 a thus extends through anarea of the flexible band positioned between the first clamping element52 a or 62 a or 72 a and the component T3, as well as an area of theband positioned on the outer side 57 a of the clamping element 52 a or62 a or 72 a. For that purpose, a corresponding bored hole for receivingthe first connection element 54 a is arranged in the first clampingelement 52 a or 62 a or 72 a.

Preferably, a hollow space H is provided in the first clamping element52 a or 62 a or 72 a, through which the first connection element 54 aextends. The hollow space H is advantageously open to the component T3.Through the hollow space H, during tightening of the first connectionelement 54 a, the first clamping element 52 a or 62 a or 72 a islengthened or stretched in the transverse direction R2 of the clampingelement, thus in the longitudinal direction of the band, in order tostress or tension the pertinent band.

Advantageously, a second connection element 54 b is provided close tothe free joint area FG or close to the component T4. This secondconnection element 54 b extends—like the first connection element 54a—through the component T3, through an area of the flexible bandpositioned between the first clamping element 52 a or 62 a or 72 a andthe component T3, through the first clamping element as well as throughan area of the band positioned on the outer side 57 a of the clampingelement. A corresponding bored hole is arranged in the first clampingelement 52 a or 62 a or 72 a for receiving the second connection element54 b.

The second clamping element 52 b or 62 b or 72 b is secured on thecomponent T3 by means of a further connection element 54 c. The positionof the second clamping element is provided relative to the firstclamping element 52 a or 62 a or 72 a so that the flexible band can beguided between these. The second clamping element 52 b or 62 b or 72 bcan additionally be provided for securing a further flexible band 51 bor 61 b or 71 b of the same joint. Thereby, the course or path thereofis then opposite in relation to the center axis A and preferablysymmetrical to the course or path of the band secured on the firstclamping element.

At least two flexible bands extending oppositely in relation to a centeraxis A of the component T4 are arranged according to the invention,whereby the at least two bands are secured on at least two clampingelements extending transversely to the longitudinal direction of thecomponents T3, T4. Also more than two, thus for example four clampingelements can be used for the securing of the at least two bands. Theseare then arranged offset relative to one another in a mannertransversely to the longitudinal direction R1 of the components T3, T4in such a manner, so that the flexible bands can be laid around thecontact surfaces of the respective clamping elements while lying next toone another and extending crossed-over in the free joint area FG.

An alternative course or path of a flexible band 61 a according to theinvention is illustrated in the FIG. 4. The flexible band 61 a issecured on a first clamping element 62 a, which is arranged on theopposite side in relation to the center axis A of the component T4. Forthat purpose, the second clamping element 62 b protrudes correspondinglyfar into the extension of the cross-section of the component T4 in thedirection toward the component T3, in order to form the intersectionpoint of the corresponding extensions of the bands 61 a, 61 b in thecomponent longitudinal direction R1, which is preferably the pivot pointP of the components.

In the embodiment of FIG. 5 with the bands 71 a, 71 b, the clampingelements 72 a, 72 b are arranged in such a manner so that the passage Dformed thereby is positioned in the area of the extension of thecross-section of the component T4 to the component T3.

A contact element can be arranged according to the invention on the sideof the pressure element 15 facing toward the first component T4. Thiscontact element can comprise a sliding layer, that is positioned on thebearing support surface 15 a of the pressure element that faces towardthe first component T4. Furthermore, the side or surface of the contactelement facing toward the first component T4 can comprise a largerradius of curvature than the surface of the first component T4 facingthis surface, in order to reduce arising compressive stresses.

1. Joint arrangement comprising: a first component having a longitudinalside; a second component having an upper surface; two clamping elements;at least two cooperating bands (41 a, 41 b; 42 a, 42 b; 51 a; 51 b; 61a, 61 b; 71 a, 71 b), which are secured with first ends (E1) thereofrespectively on opposite sides of the first component (T4), and whichare secured with second ends (E2) thereof on respectively one of theclamping elements (45, 46; 52 a, 52 b, 62 a, 62 b; 72 a, 72 b) arrangedon the second component (T3), in such a manner so that the bandsintersect a longitudinal center axis (A) of the first component (T4) inopposite directions in a joint area between the components; a pressureelement (15) positioned on at least one of the clamping elements forsupporting the first component (T4); and a respective connection elementthat secures a respective one of the bands and a respective one of theclamping elements; wherein the bands extend laterally next to thepressure element and crosswise relative to one another as seen in anaxial direction (R1), and wherein the bands (41 a, 41 b; 42 a, 42 b; 51a; 51 b; 61 a, 61 b; 71 a, 71 b) are secured between respectively one ofthe clamping elements (45, 46; 52 a, 52 b, 62 a, 62 b; 72 a, 72 b) andthe second component; and wherein the bands (41 a, 41 b; 42 a, 42 b; 51a; 51 b; 61 a, 61 b; 71 a, 71 b) are respectively guided through an areabetween one of the clamping elements (45, 46; 52 a, 52 b, 62 a, 62 b; 72a, 72 b) and the second component up to an upper surface of the clampingelement positioned opposite this area, and the bands are respectivelysecured by the connection element (54 a, 54 c), that protrudes throughthe second component, the respective clamping element, and an area ofthe respective band positioned between the respective clamping elementand the second component as well as an area of the respective band onthe respective clamping element.
 2. Joint arrangement according to claim1, characterized in that the bands (41 a, 41 b; 42 a, 42 b; 51 a; 51 b;61 a, 61 b; 71 a, 71 b) are formed of at least two plies of afiber-reinforced composite material or a synthetic plastic or a textilematerial.
 3. Joint arrangement according to claim 1, characterized inthat the bands (41 a, 41 b; 42 a, 42 b; 51 a; 51 b; 61 a, 61 b; 71 a, 71b) each extend in a longitudinal direction thereof at an angle βrelative to the axial direction, whereby the angle β amounts to notequal to 90 degrees for taking up shear forces to be transmitted throughthe joint arrangement.
 4. Joint arrangement according to claim 1,characterized in that the respective clamping element comprises a hollowspace (H) that is deformable by the respective connection element inorder to change an extension dimension of the respective clampingelement extending in a longitudinal direction of the respective band fortensioning the band.
 5. Joint arrangement according to claim 1,characterized in that the bands (41 a, 41 b; 42 a, 42 b; 51 a; 51 b; 61a, 61 b; 71 a, 71 b) are arranged one behind another as seen in theaxial direction.
 6. Joint arrangement according to claim 1, furthercomprising a contact element that is arranged on a side of the pressureelement (15) facing toward the first component (T4).
 7. Jointarrangement according to claim 6, characterized in that the contactelement comprises a sliding layer, which is positioned on a surface ofthe pressure element that faces toward the first component (T4). 8.Joint arrangement according to claim 6, characterized in that the sideof the contact element facing toward the first component (T4) comprisesa larger radius of curvature than the surface of the first component(T4) facing toward this side, in order to reduce arising compressivestresses.
 9. A joint arrangement comprising: a first component and asecond component, wherein said first component is arranged with alongitudinal edge thereof adjacent to and running in a longitudinaldirection along a major surface of said second component, and wherein ajoint area is formed between said longitudinal edge of said firstcomponent and said major surface of said second component; a pressureelement that is arranged in said joint area between said longitudinaledge of said first component and said major surface of said secondcomponent, and that is adapted to support said first component relativeto said second component; a first clamping element and a second clampingelement that are respectively secured on said major surface of saidsecond component; a first band that has a first portion thereof securedon a first side of said first component and has a second portion thereofsecured between said first clamping element and said second component; asecond band that has a first portion thereof secured on a second side ofsaid first component opposite said first side, and has a second portionthereof secured between said second clamping element and said secondcomponent; and securing elements that secure said bands and saidclamping elements to said second component; wherein respective thirdportions of said bands between said first and second portions thereofrespectively intersect a major plane of said first component in saidjoint area, and wherein said third portions of said bands extend throughsaid joint area laterally next to, or between portions of, said pressureelement; and wherein said second portion of each one of said bandsextends between a respective one of said clamping elements and saidsecond component and around a side of said respective one of saidclamping elements onto a surface of said respective one of said clampingelements facing toward said first component, and wherein said bands andsaid clamping elements are secured to said second component by saidsecuring elements that respectively pass through said second component,a respective one of said clamping elements, and a respective one of saidsecond portions of said bands at a location between said respective oneof said clamping elements and said second component and a location onsaid surface of said respective one of said clamping elements.
 10. Thejoint arrangement according to claim 9, wherein said pressure element isarranged on one of said clamping elements, with said one of saidclamping elements interposed between said pressure element and saidsecond component.
 11. The joint arrangement according to claim 9,wherein said third portions of said bands extend through said joint arearespectively at positions that are offset one behind another in saidlongitudinal direction of said first component along said major plane ofsaid first component.
 12. The joint arrangement according to claim 9,wherein said bands each respectively comprise at least two plies of oneor more materials selected from the group consisting of fiber-reinforcedcomposite materials, synthetic plastic materials, or textile materials.13. The joint arrangement according to claim 12, wherein said at leasttwo plies are not secured to one another respectively in said thirdportions of said bands extending through said joint area.
 14. The jointarrangement according to claim 9, wherein each one of said bands extendswith a longitudinal extension thereof running at an angle not equal to90 degrees relative to said longitudinal direction of said firstcomponent.
 15. The joint arrangement according to claim 9, wherein eachone of said clamping elements respectively has a hollow space therein sothat said respective clamping element is deformable by said securingelement in a direction so as to apply a tension to a respective one ofsaid bands that is secured by said respective clamping element.
 16. Thejoint arrangement according to claim 9, wherein said first clampingelement extends on said second component on a side of said major planeopposite said first side of said first component, and said secondclamping element extends on said second component on a side of saidmajor plane opposite said second side of said first component.
 17. Thejoint arrangement according to claim 9, wherein each one of said bandsrespectively intersects and crosses over said major plane of said firstcomponent only once.
 18. The joint arrangement according to claim 9,wherein said first clamping element extends on said second component ona side of said major plane corresponding to said first side of saidfirst component, and said second clamping element extends on said secondcomponent on a side of said major plane corresponding to said secondside of said first component.
 19. The joint arrangement according toclaim 9, wherein each one of said bands respectively intersects andcrosses over said major plane of said first component exactly twice. 20.The joint arrangement according to claim 9, further comprising a contactelement arranged on a side of said pressure element facing toward saidfirst component.
 21. The joint arrangement according to claim 20,wherein said contact element comprises a sliding layer.
 22. The jointarrangement according to claim 20, wherein said longitudinal edge has afirst curved surface facing toward said contact element, said contactelement has a second curved surface facing toward and contacting saidfirst curved surface of said longitudinal edge of said first component,and said second curved surface has a larger radius of curvature thansaid first curved surface.